Telescopic fluid hoist



'Aug. 18, 1931. J. P. HEM. ET AL TELESCOPIC FLUID HOIST Filed March 15, 195o Aug. 18, 1931. J. R HEIL ET AL 1,819,168

TELESCOPIC FLUID HOIST IN VEN TORS Aug.l8, 1931. J. P. HEM. E1' AL 1,819,168

TELEscoPIc FLUID Hols'r Filed March 1:5, 1930 5 sheets-sheet 5 III - IN VEN TORS M M 7 QTTORNEYS.

Patented Aug. 18, 1931 UNITED STATES PATENT OFFICEv 4 TULIUS P. HEIL, OF MILWAUKEE, AND GEORGE L. LANDRY, 0F WEST ALLIS, WISCONSIN,

ASSIGNORS TO THE HEIL CO., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN TELESCOPIC FLUID HOIST Application led March 13, 1930. Serial' No. 435,454.

This invention relates to improvements in telescopic fluid hoists, more particularly, although not solely, adapted for trucks hav ing dumping bodies.

It is one of the objects of the present invention to provide a telescopic liuid hoist of the high lift type which maybe used with a truck for unusual delivery conditions to permit raising the truck body to a considerable l@ height before discharging its contents.

A further object of the invention is to provide a telescopic fluid hoist which may be operated from the power means of the truck and be controlled from-the cab of the truck.

A further object of the invention is to provide a telescopic fluid hoist which may be used for a dump body truck to move the body to various elevated positions.. and dumping M inclinations.

A further object of the invention is to provide a telescopic iiuid hoist in which, when the pistons reach their outermost positions, the fluid under pressure which moves the pistons, will automatically stop and thus eliminate injury to the parts.

A further object of the invention is to rovide a telescopic fluid hoist having means or by-passing the oil, used as the fluid medium, from one side of the pistons to the supply tankto permit the pistons to move inwardly from their outer positions.

A further object of the invention is to provide a telescopic fluid hoist having a fixed tank for receiving and holding the displaced oil when the pistons are in their innermost positions.

A further object of the invention is to provide a telescopic fluid hoist having a gear pump, a check valve and a rotary valve for 4 forcing and controlling the flow of the fluid from one side of the pistons to the supply tank and for automatically maintaining the pistons in any position of adjustment.

A further object of the invention is to provide a telescopic fluid hoist in which one piston is positioned within another to provide a comparatively long stroke device in connection with'a relatively short cylinder.

A further object of the invention is to provide atelescopic fluid hoist which is'of simple construction, is strong and durable and is well adapted .for the purpose described. Y

With the above and other objects in view thevinvention consists of the improved telescopic fluid hoist and its parts and combinations as set forth in the claims, and all equivalentsthereof.

In the accompanying drawings in which the same reference characters indicate the same parts in all of thel views:

Fig. l is a side view of a motor truck part provided with the improved telescopic fluid hoist, the view also illustrating by dotted lines, the body portion in different tilted positions;

Fig. 2 is a front view of the cylinder and parts connected thereto, some of the parts being in section;

Fig. 3 is a vertical sectional View thereof taken on line 3-3 of Fig. 2;

Fig. 4 is a top view of the hoist and parts connected thereto;

Fig. 5 is a side detail view of the controlling valves and connected parts; and

Fig. 6 is a vertical sectional detail view taken on line 6-6 of the parts shown in j Fig. 5.

Referring to the drawings the numeral 8 indicates a portion of a motor truck, 9 the side members of the chassis or frame, 10 the cab or seat portion and 11 the tiltable load carrying body of the truck. Said body portion is mounted upon upper spaced side I-beams 12 which form part of the hoist mechanism exemplifying one use of the hoist. Lower spaced side I-beams 13 forming the lower portion of the hoist mechanism are rigidly mounted upon the side members of the truck by brackets 14. Saidv lower side beams 13 at their opposite end portions are connected together in spaced relation by transverse pairs of I-beams 15 which have upwardly extending brackets 16 for supporting the body beams 12 thereon when said beams are in their lower position.

The longitudinally extending beams 12 and 13 are connected together by means of diagonally extending pairsfoflever arms 17 and 18 which cross each other and are pivotally connected together by a transverse pivot shaft 19.

The levers 17 are formed in two parts and the adjacent ends of the parts overlap each other and are pivotally connected to the short shaft 19 by bearings 20 and 21 and are limited as to pivotal movement in one direction by an adjustable stop bolt member 22.

A pair of spaced cylinders 23 arev pro- O`vided with upper outwardly projecting porare provided with 4piston rods 32 which eX- tions 24 having alined trunnion recesses 25 for receiving the inwardly extending trunnions 26 of the trunnion brackets 27. Said trunnion brackets extend' over and are bolted to the I-beams 13. The cylinders 23 are pivotally supported from said trunnions and extend downwardly therefrom and are provided with inner tubular piston cylinders 28 which contain pistons 29. Both the piston cylinders 28 and the pistons 29 have packing rings 30 and 31 and the pistons 29 i ranged the upward movement of thevpiston cylinders and the pistons will lift the truck body to the desired height and tilt the same and the pivotal connections of the cylinders with the I-beams will permit the cylinders' and pistons to tilt while the body is traveling its arc of movement.

The cylinders 23 are formed with lower duct ports 36 which extend upwardly and are connected to the outlet ports 37 of a rotary gear pump 38 connected to both spaced cylinders 23. Said outlet port is provided with a spring pressed ball valve 39 which opens with the flow of the fluid towards the outlet duct ports 37 and 36 to force the cylinder pistons and the pistons upwardly. When forced upwardly the valve prevents the return of the fluid and the cylinder pistons and the pistons are held in their upper positions.

The pump inlet duct 40 extends rearwardly from the pump gears 41 and a part flexible pipe 42 connects the duct to a storage tank 43 which is mounted on the rear portion of the lower frame 13 so that when the pump is in operation the fluid will be drawn from the storage tank by the pump and forced beneath the pistons to elevate and tilt the body.

A11 automatically actuated valve 44 intersects the duct 40 and its arm 45 is connected to a lever 46, and the lever is connected to an actuating rod 47 which slidably extends through a transverse pivoted bar 17 of the Clever arms 17 andis provided with spaced stop collars 47 and 47" to limit the movement of the rod in both directions. transverse portion 17 slides on the rod- 47 the movement of the member and the tilting of the'cylinders will lcause the valve to turn and substantially close the duct to the tank when the pistons are in their uppermost position.

A by-pass duct 48 extends from the duct 40 adjacent the valve 44 and a controlling valve 49 intersects said duct 48 to permit the Huid medium to circulate through the pump without doing any damage to the parts when the ypistons are in their lowermost position. The valve 49 also serves to permit the fluid medium to flow from beneath the pistons to and through the ilexible tube 42 and back into the tank 43 when it is desired to lower the dump body.

A controlling rod 50' connected to the arm 51 of the valve 49 extends to a control lever 52' mounted in the cab 10 of the truck.

The pump 38 is of the ordinary two gear type and one of the gears is provided with a shaft 53 having a universal joint connection 54 with a shaft 55 extending to apower take off 56 of the transmission 57 of the truck. A rod 58 extending from the take off 56 to a control lever 59 mounted in the cab 10 of the truck provides for controlling the actuation of the take off.

In the event that any of the fluid medium or oil seeps by the piston rings it is permitted to How back to the tank 43 through flexible tubes 60 and 61, the tubes 60 extending between the cylinders 23 and the tank 43, and the tubes 61 extending between the piston cylinders 28 and the said tank. The vseepage oil mentioned will drain back to the tank when pistons and piston cylinders are in their upper position.

As the v In Ioperation the transmlssion control lever is turned to start the rotation of the pump which will draw oil from the tank and force it through the ducts and into the lower portions of the cylinders 23 and piston cylinders 28. The pressure of the 011 will now force the pistons or the piston cylinders or both upwardly to tilt or elevate the truck body as indicated by dotted lines in Fig. 1, the tilt or elevation being controlled by the position of the bolt 22 in the holes provided therefor.

When the pistons and the piston cylinders reach their uppermost position the valve 44 will be automatically turned to substantially close off the supply of oil from the 'tank so that the continued operation of the elevation of the body as the ball check valve 49 will stop the return iow of the oil and the parts will remain at rest.- While the pump is in operation to elevate the body the valve 49 is, of course, closed, and when it is desired to lower the body the said valve is opened as shown in Fig. 3 to permit the .oil to flow therethrough and directly into the tube 42 and the tank, the speed of lowering being controlled by the turning'of the valve to increase or decrease the size of the opening through which the oil Hows.

It is to be understood that one or any number of cylinders and pis ons may be used as desired without departing from the spirit and scope of the invention.

From the foregoing description it will be seen that the telescopic fluid hoist is of very simple construction, is strong and durable and is Well adapted for the purpose described.

What is claimed as the invention is:

1. A telescopic fluid hoist, comprising a movable cylinder having a duct in communication with the bore of the cylinder, a piston-cylinder reciprocally positioned within the bore of the cylinder and having a tubular` portion which extends through the head -of the cylinder and also having an opening extending through the piston portion, a piston reciprocally positioned within thebore of the piston-cylinder and having a piston rod which extends through the head of the piston-cylinder, a fluid medium tank adjacent the cylinder, a duct connecting the tank to the 4cylinder duct, a pump intersecting the ducts between the tank and the cylinder bore, a check valve permitting the flow of the fluid medium from the pump only in one direction, a pump by-pass duct extending between the cylinder and the tank ducts, an automatic valve operable by the movenient of said cylinder and movable to intercept the flow between the tank and the pump when said piston and piston cylinder have been fully elevated, and a manually actuated valve controlling the flow of the fluid medium through the by=pass duct to lower said piston and piston cylinder. A

2. A telescopic fluid hoist, comprising a movable cylinder having a duct in communication with the bore of the cylinder, a piston-cylinder reciprocally positioned within the bore of the Vcylinder and having a tubu- F lar portion whichextends through the head of the cylinder and also having an opening extending through the piston portion, a piston reciprcally positioned within the bore of the piston-cyhnder and having a piston rod which extends through the head of the piston-cylinder, a fluid medium tank adjacent the cylinder, a duct connecting the tank to the cylinder duct, a pump intersecting the ducts between the tank and the cylinder bore, an automatic valve operable by the movement of vsaid cylinder and `intersecting the ducts between the pump and tank when said pistonand piston cylinder have been fully elevated, a pump by-pass duct extending between the cylinderduct and the automatic valve, ducts connected to the cylinder and the piston-cylinder and the tank to return to the tank fluid medium which may pass between the piston and the piston-cylinder and between the piston-cylinder and the cylinder, and a valve controlling the flow through the by-pass duct to lower said piston-and piston-cylinder.

3. A telescopic fluid hoist, comprising a movable cylinder having a duct in communication with the bore of the cylinder, a piston-cylinder reciprocally positioned within the bore of the cylinder and having a tubular portion which extends through' the head of the cylinder and also having an opening extending through the piston portion, a piston reciprocally positioned within the bore of the piston-cylinder and havin a piston rod which extends through the hea of the piston-cylinder, a fluid medium tank adjacent the cylinder, a duct connecting the tank to the cylinder duct, a pump intersecting the ducts between the tank and the cylinder bore, a check valve permitting the flow of the Huid medium from the pump only in one direction, a pump by-pass duct extending between the cylinder and the tank ducts, an automatic valve operable by the movement of said cylinder to control the flow between the tank and the pump when said piston and piston cylinder have been fully elevated, ducts connected to the cylinder and the piston-cylinder and the tank to return to the tank fluid medium which may pass between the piston and the piston-cylinder and between the piston-cylinder and the cylinder, and a manually actuated valve controlling the flow of the iuid medium through the by-pass duct to lower said piston and piston cylinder.

4. In combination, a laterally tiltable cylinder, a piston reciprocable within said cylinder, a source of fluid supply, a pump for transferring iuid from said source to said cylinder to move said piston, a check valve permitting flow of fluid through said pump in one direction only, a valve automatically operable by the tilting of said cylinder to interrupt communication between said pump and said source whensaid piston has been fully elevated, means forming a pump by-pass duct connecting said valve and said cylinder, and another valve for controlling the flow of fluid through said by-pass duct to lower said piston.

In testimony whereof we alix our signatures.

JULIUS P. HEIL. GEORGE L. LANDRY.

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